Jsp-图片验证码及刷新

1、1.图片验证码的实现主要的技术点是如何生成一个图片。生成图片可以使用java.awt包下的类来实现。我们先写一个简单的生成图片的程序HelloImage.java。以下是代码部分。（是我在做留言板项目时的部分代码）HelloImage .javaview plaincopy to clipboardprint?package liuyanban;import java.awt.Color;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOExcept

2、ion;import javax.imageio.ImageIO;/* 生成图片*/public class HelloImage public static void main(String args)BufferedImage image = new BufferedImage(80, 50,BufferedImage.TYPE_INT_RGB);/建立BufferedImage对象。指定图片的长度宽度和色彩。Graphics g = image.getGraphics();/取得Graphics对象，用来绘制图片。g.setColor(new Color(255,255,255);/绘制

3、图片背景和文字。g.fillRect(0, 0, 80, 25);g.setColor(new Color(0,0,0);g.drawString(HelloImage,6,16);g.dispose();/释放Graphics对象所占用的资源。tryImageIO.write(image, jpeg, new File(C:helloImage.jpeg);/通过ImageIO对象的write静态方法将图片输出。catch(IOException e)e.printStackTrace();package liuyanban;import java.awt.Color;import java

4、.awt.Graphics;import java.awt.image.BufferedImage;import java.io.File;import java.io.IOException;import javax.imageio.ImageIO;/* 生成图片*/public class HelloImage public static void main(String args)BufferedImage image = new BufferedImage(80, 50,BufferedImage.TYPE_INT_RGB);/建立BufferedImage对象。指定图片的长度宽度和色

5、彩。Graphics g = image.getGraphics();/取得Graphics对象，用来绘制图片。g.setColor(new Color(255,255,255);/绘制图片背景和文字。g.fillRect(0, 0, 80, 25);g.setColor(new Color(0,0,0);g.drawString(HelloImage,6,16);g.dispose();/释放Graphics对象所占用的资源。tryImageIO.write(image, jpeg, new File(C:helloImage.jpeg);/通过ImageIO对象的write静态方法将图片输

6、出。catch(IOException e)e.printStackTrace();view plaincopy to clipboardprint?*viewclipboardprint?2.生成验证码图片的类2.生成验证码图片的类view plaincopy to clipboardprint?package liuyanban;plaincopy toimport java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.I

7、OException;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.http.HttpServletResponse;/* 生成验证码图片的类*/public class RandImgCreater private static final String CODE_LIST ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890;private HttpServletResponse response = null;pri

8、vate static final int HEIGHT = 20;private static final int FONT_NUM = 4;private int width = 0;private int iNum = 0;private String codeList = ;private boolean drawBgFlag = false;private int rBg = 0; =private int gBg = 0;private int bBg = 0;public RandImgCreater(HttpServletResponse response) this.resp

9、onse = response;this.width = 13 * FONT_NUM + 12;this.iNum = FONT_NUM;this.codeList = CODE_LIST;public RandImgCreater(HttpServletResponse response,int iNum,String codeList) this.response = response;this.width = 13 * iNum + 12;this.iNum = iNum;this.codeList = codeList;public String createRandImage()Bu

10、fferedImage image = new BufferedImage(width, HEIGHT,BufferedImage.TYPE_INT_RGB);Graphics g = image.getGraphics();Random random = new Random();if ( drawBgFlag )g.setColor(new Color(rBg,gBg,bBg);g.fillRect(0, 0, width, HEIGHT);elseg.setColor(getRandColor(200, 250);g.fillRect(0, 0, width, HEIGHT);for (

11、int i = 0; i 155; i+) g.setColor(getRandColor(140, 200);int x = random.nextInt(width);int y = random.nextInt(HEIGHT);int xl = random.nextInt(12);int yl = random.nextInt(12);g.drawLine(x, y, x + xl, y + yl);g.setFont(new Font(Times New Roman, Font.PLAIN, 18);String sRand=;for (int i=0;i 255)fc = 255;

12、if (bc 255)bc = 255;int r = fc + random.nextInt(bc - fc);int g = fc + random.nextInt(bc - fc);int b = fc + random.nextInt(bc - fc);return new Color(r, g, b);package liuyanban;import java.awt.Color;import java.awt.Font;import java.awt.Graphics;import java.awt.image.BufferedImage;import java.io.IOExce

13、ption;import java.util.Random;import javax.imageio.ImageIO;import javax.servlet.http.HttpServletResponse;/* 生成验证码图片的类*/public class RandImgCreater private static final String CODE_LIST ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890;private HttpServletResponse response = null;private

14、static final int HEIGHT = 20;private static final int FONT_NUM = 4;private int width = 0;private int iNum = 0; =private String codeList = ;private boolean drawBgFlag = false;private int rBg = 0;private int gBg = 0;private int bBg = 0;public RandImgCreater(HttpServletResponse response) this.response

15、= response;this.width = 13 * FONT_NUM + 12;this.iNum = FONT_NUM;this.codeList = CODE_LIST;public RandImgCreater(HttpServletResponse response,int iNum,String codeList) this.response = response;this.width = 13 * iNum + 12;this.iNum = iNum;this.codeList = codeList;public String createRandImage()Buffere

16、dImage image = new BufferedImage(width, HEIGHT,BufferedImage.TYPE_INT_RGB);Graphics g = image.getGraphics();Random random = new Random();if ( drawBgFlag )g.setColor(new Color(rBg,gBg,bBg);g.fillRect(0, 0, width, HEIGHT);elseg.setColor(getRandColor(200, 250);g.fillRect(0, 0, width, HEIGHT);for (int i

17、 = 0; i 155; i+) g.setColor(getRandColor(140, 200);int x = random.nextInt(width);int y = random.nextInt(HEIGHT);int xl = random.nextInt(12);int yl = random.nextInt(12);g.drawLine(x, y, x + xl, y + yl);g.setFont(new Font(Times New Roman, Font.PLAIN, 18);String sRand=;for (int i=0;i 255)fc = 255;if (b

18、c 255)bc = 255;int r = fc + random.nextInt(bc - fc);int g = fc + random.nextInt(bc - fc);int b = fc + random.nextInt(bc - fc);return new Color(r, g, b);view plaincopy to clipboardprint?*viewclipboardprint?3.调用生成验证码图片：img.jsp3.调用生成验证码图片：img.jspview plaincopy to clipboardprint?* 4.测试,验证，刷新: name=code% page plaincopy toview plaincopy to clipboardprint?response.setHeader(Pragma,No-cache); name=code% page * 4.测试,验证，刷新: view plaincopy to clipboardprint? view plaincopy to clipboardprint?* *view plaincopy to clipboardprint?view plaincopy to clipboardprint?4.测试,验证，刷新: 4.测试,验证，刷新:view plainc